September weather forecastGretna, FL
September
Weather in September
September, the first month of the autumn in Gretna, is still a hot month, with an average temperature fluctuating between 69.4°F (20.8°C) and 87.3°F (30.7°C).Temperature
As September unfolds, the average high-temperature reaches a still tropical 87.3°F (30.7°C), hinting at a slight fluctuation from the previous month. In the month of September, the average low-temperature usually rests at an agreeable 69.4°F (20.8°C).Heat index
During September, the heat index is computed to be a torrid 102.2°F (39°C). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.Evaluating the heat index requires understanding its values in the shade and with gentle winds. Direct exposure to sunshine could lead to a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', melds the effects of warmth and moisture to generate a feeling of heat. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. Heat-related complications, like dehydration, can manifest if the body's heat gain exceeds its dissipation capacity.
Humidity
In Gretna, the average relative humidity in September is 77%.Rainfall
In September, the rain falls for 19.4 days. Throughout September, 3.35" (85mm) of precipitation is accumulated. In Gretna, during the entire year, the rain falls for 184.9 days and collects up to 37.6" (955mm) of precipitation.Snowfall
In Gretna, snow does not fall in February through December.Daylight
In September, the average length of the day is 12h and 20min.On the first day of September, sunrise is at 7:15 am and sunset at 8:01 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:24 pm EDT.
Sunshine
In Gretna, the average sunshine in September is 8.6h.UV index
In Gretna, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: An average UV index of 6 in September transforms into this advice:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Gretna, FL
- Average high temperature in September: 87.3°F
The warmest months (with the highest average high temperature) are July and August (90.7°F).
The month with the lowest average high temperature is January (60.4°F).
- Average low temperature in September: 69.4°F
The month with the highest average low temperature is August (73.6°F).
The coldest month (with the lowest average low temperature) is January (42.3°F).
Average pressure in September
Gretna, FL
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.98"Hg).
Average wind speed in September
Gretna, FL
- Average wind speed in September: 4.9mph
The windiest months (with the highest average wind speed) are January and March (6.6mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Gretna, FL
- Average humidity in September: 77%
The months with the highest relative humidity are August and December (78%).
The month with the lowest relative humidity is May (72%).
Average rainfall in September
Gretna, FL
- Average rainfall in September: 3.35"
The wettest month (with the highest rainfall) is August (5.08").
The driest month (with the least rainfall) is November (1.46").
Average rainfall days in September
Gretna, FL
- Average rainfall days in September: 19.4 days
The month with the highest number of rainy days is July (26.1 days).
The month with the least rainy days is November (8.1 days).
Average snowfall in September
Gretna, FL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.04").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Gretna, FL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.2 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Gretna, FL
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).
- Average sunshine in September: 8h and 36min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
Gretna, FL
- Average sunshine days in September: 9.3 days
The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is July (3.4 days).
Average UV index in September
Gretna, FL
- Average UV index in September: 6
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover in September
Gretna, FL
- Average cloud cover in September: 32
The month with the most cloud cover is December (Cloud cover 43).
The months with the least cloud cover are May and October (Cloud cover 29).
Average visibility in September
Gretna, FL
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, May, June, October and November (6mi).
The months with the lowest visibility are July, August, September and December (5mi).
